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While several African countries saw their planned U.S. tariffs reduced significantly this week, the White House refused to ease its rate for South Africa.Anna Moneymaker/Getty Images

After months of intense effort to negotiate a U.S. trade deal, South Africa has been left out in the cold, facing a renewed 30-per-cent tariff as the Trump administration snubbed its offer of multibillion-dollar concessions.

The tariff, virtually unchanged from a levy that was announced in April and then suspended, is the latest punishing blow against South Africa from U.S. President Donald Trump, who has campaigned relentlessly against the country since the beginning of his second term in office this year.

The tariff was among the highest to be imposed on any U.S. trading partner in the latest round of White House announcements on Thursday night. According to South Africa’s central bank, it could trigger the loss of 100,000 jobs, a potentially disastrous setback for an already fragile economy.

For months, Mr. Trump has falsely accused South Africa of seizing farmland and perpetrating a “genocide” against its white minority. Earlier this week, he complained again of “very bad policies” in the country, revealing that he might boycott the November G20 summit in Johannesburg.

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While several African countries saw their planned U.S. tariffs reduced significantly in this week’s announcement, the White House refused to ease its rate for South Africa, which had been set at 31 per cent in April.

In their talks since then, South Africa has offered billions of dollars in trade concessions. It proposed that its businesses would invest US$3.3-billion in the U.S. mining industry and other sectors, and it offered to import US$12-billion in liquefied natural gas over a 10-year period.

But after submitting the offer, the country failed to obtain even a reply from the Trump administration. It sought an extension of the Aug. 1 deadline, but did not get one.

“We engaged with the U.S. trade representative’s office and they’re unable to give us a firm indication as to what it is that we need to do now to get to the point of a decision,” Trade and Industry Minister Parks Tau told the national broadcaster SABC on Thursday.

“They suggested that maybe we present a revised offer,” Mr. Tau said.

While still hoping to revive the negotiations before the tariff takes effect on Aug. 7, the South African government is meanwhile scrambling to provide help to its exporters. Key industries such as auto manufacturing and citrus farming are expected to be badly hit.

President Cyril Ramaphosa said he noted the U.S. tariff announcement “with concern.” In a statement on Friday, he pledged to pursue “all diplomatic efforts” to reach a trade deal, while also promising an intensified effort to diversify South Africa’s trade markets. China, already the country’s biggest trading partner, could be a beneficiary of the strategy.

The 30-per-cent tariff is highly unequal, since the average tariff on U.S. goods entering South Africa is just 7.6 per cent, according to Mr. Ramaphosa.

His trade minister, Mr. Tau, promised an urgent set of aid measures for South African businesses, including an export support desk and possible tax incentives. “This tariff hike poses a direct threat to our export capacity,” he said in a statement.

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The Democratic Alliance, the second-biggest party in South Africa’s parliament and a member of the country’s governing coalition, said the announcement of the 30-per-cent tariff is “a devastating outcome for South Africa.”

The new tariff is just one of the blows that South Africa has suffered at Mr. Trump’s hands this year. He has also terminated all U.S. foreign aid to the country and threatened to impose an additional 10-per-cent tariff on South Africa and other members of the BRICS partnership, which was originally formed by Brazil, Russia, India, China and South Africa and has since expanded to include Egypt, Ethiopia, Indonesia, Iran and the United Arab Emirates. His previously announced 25-per-cent tariff on automobiles has severely damaged South Africa’s car exports to the United States.

Elsewhere in Africa, many countries saw a reduction in their U.S. tariffs this week, but others are still left with significant rates. Algeria and Libya were hit with 30-per-cent levies, Tunisia is facing a 25-per-cent rate, and many others were given 15-per-cent tariffs.

Lesotho, the small mountainous kingdom that was inexplicably hit with a 50-per-cent tariff in April, saw its rate reduced to 15-per-cent on Thursday. But it might be too late to undo the damage, since some textile factories there have already laid off thousands of workers. The factories had been beneficiaries of a U.S.-Africa free-trade agreement that now seems dead.